Matt, Vanquisher of 'Thews

This creature is not affected by Commander Tax
Millworks - {t}, discard a card. All opponents mill
X cards based on the discarded card's rarity:
•Common - discard 1 card
•Uncommon - discard 2 cards
•Rare-discard 3 cards
{bull}Mythic Rare-discard 4 cards